2002 NISSAN TERRANO unit

5. Bleed the air from the rear brake piping.
6. To adjust the LSV correctly, proceed as follows:
a. With unladen vehicle (12 liters of fuel, radiator coolant and
engine oil are full). Spare tire, hand tools and mats in desig-
nated positions. Check the length of LSV spring ªLº.
b. If the spring length is different from that specified, move the
regulation lever (2) until the specified value is obtained. Move
the LSV lever (1) until it contacts the stopper bolt and recheck
the spring length.
Sensor spring length ªLº
Hardtop: 201 mm (7.913 in)
Wagon: 197.5 mm (7.776 in)
NOTE: Do not disturb stopper bolt.
c. Start the engine and run it at idling speed.
d. Slowly depress the brake pedal until an input pressure of 4,805
kPa (48.1 bar, 49 kg/cm
2, 697 psi) is obtained (at the front axle
pressure gauge) and an output pressure of 1,736 - 2,501 kPa
(18 - 26 bar, 17.7 - 25.5 kg/cm
2, 252 - 363 psi) is obtained (at
the rear axle pressure gauge).
If the output pressure at the rear axle pressure gauge is not within
the specified values, adjust LSV spring length as described under
b) until the output pressure measured is within the specified range.
Unit: kPa (bar, kg/cm2, psi)
Front axle* 4,805 (48.1, 49.0, 697)
Rear axle* 1,736 - 2,501 (18 - 26, 17.7 - 25.5, 252 - 363)
* Load conditions as indicated under 6.a, driver seat occupied.
EBR022
NBR313
EBR026
LOAD SENSING VALVE
Inspection and Adjustment (Cont'd)
BR-13

Purpose
The Anti-lock Brake System (ABS) with an integrated Electronic Brake force Distribution (EBD) system con-
sists of electronic and hydraulic components. It allows you to control the braking force so that wheel lock can
be avoided during braking.
The advantages of ABS with EBD
1) Better tracking performance through improved steering wheel control.
2) Improved maneuverability and safer vehicle control.
3) Improved vehicle stability by preventing flat spins.
4) Shorter stopping distance and optimal utilisation of the rear brakes under many different circumstances.
Operation
IABS with EBD has self-test capabilities. The ABS warning lamp is illuminated for 1 second each time the
ignition switch is turned ªONº. After the engine is started, the ABS warning lamp turns off. An ABS self-test
is performed the first time the vehicle reaches 6 km/h (4 MPH) to ensure the system is operational. A
mechanical noise may be heard as the ABS performs this self-test and is a normal part of the self-test
feature. If a malfunction is detected during this check, the ABS warning lamp will stay on.
During the self-test, it also performs a EBD check when it detects a failure the ABS warning light will go
on simultaneously with the brake warning light and an audible sound will sound constantly.
IEBD system will only operate when the ABS is not in active status and it uses the inlet valves of ABS con-
trol unit to limit the pressure to the rear wheels when they tend to go into slip.
IWhen the vehicle speed is less than 10 km/h (6 MPH) the ABS system does not operate.
IWhile driving, a mechanical noise may be heard during ABS operation, this is a normal system condition.
ABS Hydraulic Circuit
q1Inlet solenoid valve
q
2Outlet solenoid valve
q
3Reservoirq
4Pump
q
5Motorq
6By pass check valve
q
7Damper
NBR346
ANTI-LOCK BRAKE SYSTEM
BR-37

System Description
Sensor
The sensor unit consists of a gear-shaped sensor rotor and a sen-
sor element. The element contains a bar magnet around which a
coil is wound. The sensor is installed on the back of the brake rotor
and the rear brake drum.
As the wheel rotates, the sensor generates a sine-wave pattern.
The frequency and voltage increase(s) as the rotating speed
increases.
Control unit
The control unit computes the wheel rotating speed by the signal
current sent from the sensor. Then it supplies a DC current to the
actuator solenoid valve. It also controls ON-OFF operation of the
valve relay and rotor relay. If any electrical malfunction should be
detected in the ABS or EBD system, the control unit causes the
warning lamp(s) to light up, combined with an audible sound.
In this condition, the ABS or EBD will be deactivated by the control
unit, and the vehicle's brake system reverts to normal operation.
(Fail-safe mode)
YBR262
SBR124B
YBR263
ANTI-LOCK BRAKE SYSTEM
BR-38

G SENSOR
The G sensor analyses deceleration during braking to determine whether the vehicle is being driven on a road
with low surface resistance () (snow-covered road, etc.). The ABS control unit uses the signal from the
deceleration sensor to compensate for road surface conditions when controlling the braking operation.
NBR136
ANTI-LOCK BRAKE SYSTEM
System Description (Cont'd)
BR-39

ACTUATOR AND ELECTRIC UNIT
The actuator and electric unit contains:
IAn electric motor and pump
ITwo relays
ISix solenoid valves, each inlet and outlet for
Ð LH front
Ð RH front
Ð Rear
IABS control unit
These components control the hydraulic circuit. The ABS control
unit directs the actuator to increase, hold or decrease hydraulic
pressure to all or individual wheels. The ABS actuator and electric
unit cannot be disassembled and has to be serviced as an assem-
bly.
YBR299
ANTI-LOCK BRAKE SYSTEM
System Description (Cont'd)
BR-40

REAR SENSOR ROTOR
Removal
IRemove the sensor rotor using Tool.
Installation
Install the sensor rotor using suitable drift and press.
IAlways replace sensor rotor with new one.
IPay attention to the direction of front sensor rotor as shown in
figure.
CONTROL UNIT
Location: Built-in ABS actuator.
When disconnecting the harness connector, pull the lever as
shown in figure.
G SENSOR
Always replace G sensor if bumped or dropped. Otherwise,
performance characteristics of G sensor will be changed,
which in turn alters ABS control performance characteristics.
SBR401D
SBR402D
NBR212
NBR127
ANTI-LOCK BRAKE SYSTEM
Removal and Installation (Cont'd)
BR-44

ACTUATOR
Removal
1. Disconnect battery cable.
2. Drain brake fluid. Refer to BR-5.
3. Unlock the slider then disconnect the electrical harness con-
nectors from ABS control unit.
4. Identify each brake pipe with corresponding actuator port hole
and mark them accordingly.
5. Disconnect brake pipes and move them away from actuator. Do
not force brake pipes so as to kink them or bend them exces-
sively.
Ensure that brake fluid does not come into contact with
any parts.
YBR299
ANTI-LOCK BRAKE SYSTEM
Removal and Installation (Cont'd)
BR-45

6. Loosen/remove mounting nuts between actuator and bracket.
Installation
CAUTION:
After installation, pay attention to the following points:
IRefill brake fluid and bleed air. Refer to ªCHECK AND
ADJUSTMENTº, BR-5 and ªBleeding Brake Systemº,
ªBRAKE HYDRAULIC LINEº, BR-8, respectively.
1. Install actuator on bracket without tightening fixings.
2. Assemble brake tubes to actuator without tightening tube nuts.
Ensure that correct tubes are connected to each port.
3. Fully tighten actuator and bracket fixings to specified torque.
4. Fully tighten flare nuts to specified torque, BR-9.
5. Secure ABS control unit harness connector and battery cable.
ANTI-LOCK BRAKE SYSTEM
Removal and Installation (Cont'd)
BR-46